GB190614433A - Improvements in the Regulation of Continuous Current Electric Motors. - Google Patents

Abstract

14,433. Iles, C. H., and Armistead, W. June 23. Distributing.-To prevent the variation of the speed of continuous-current motors due to varying field current caused by the heating of the field coils, the shunt field windings of a group of motors for cotton-mill driving are connected in series in a separate circuit across the supply mains or current source, and a constant exciting-current is maintained therein. The field windings may be connected in series with a rheostat ; or, the terminal voltage of the field circuit may be varied by means of a potentiometer; or, a rheostat and potentiometer may be combined. In the arrangement shown in Fig. 2, a small booster f, driven at constant speed by a motor g, is included in series with the motor field coils a<1>, b<1>, c<1>, and the current in the booster field coil f<1> is regulated to vary the booster volts to maintain a constant current in the windings a<1>, b', c<1>. In the arrangement shown, the current in the booster field is controlled manually, or by a rheostat h actuated by a small motor i with oppositely-wound potential and current coils i<1>, i<2>, as described in Specification No. 9940, A.D. 1905.